Pushed suction dredger and barge combination

ABSTRACT

A dredger comprising a floating vessel and a dredging and suction unit which is tracted by the floating vessel and travelled on the sea bottom. Silt on the sea bottom is sucked by a pump provided on the dredging and suction unit and introduced into the floating vessel through conduits and subsequently delivered to a barge provided in a recess of the floating vessel. The vessel and barge are propelled by a push-boat.

" United States Patent Sasaki et a1.

PUSHED SUCTION DREDGER AND BARGE COMBINATION Inventors: Michio Sasaki, Funabashi; Keizo Kikui, Kamagaya, both of Japan Assignee: Mitsui Shipbuilding & Engineering Co. Ltd., Tokyo, Japan Filed: July 9, 1974 Appl. No.: 486,871

Foreign Application Priority Data July 11, 1973 US. Cl 37/66; 37/72; 114/235 R Int. (ll. E02F 3/88 Field of Search 37/55, 58, 66, DIG. 8,

References Cited I UNITED STATES PATENTS Henderson 37/66 Japan 48-78647 51 Nov. 18, 1975 3,248,812 5/1966 Gardner, Jr 37/55 X 3,429,062 2/1969 Nelson 37/D1G. 8 3,820,258 Fahrner 37/72 X Primary E.\'aminerClifford D. Crowder Attorney, Agent, or Firm-Dorfman, Herrell and Skillman [57] ABSTRACT A dredger comprising a floating vessel and a dredging and suction unit which is tracted by the floating vessel and travelled on the sea bottom. Silt on the sea bottom is sucked by a pump provided on the dredging and suction unit and introduced into the floating vessel through conduits and subsequently delivered to a barge provided in a recess of the floating vessel. The vessel and barge are propelled by a push-boat.

3 Claims, 3 Drawing Figures US. Patent Nov. 18, 1975 PUSl-IED SUCTION DREDGER AND BARGE COMBINATION This invention relates to a dredger suitable for dredging the deep sea bottom.

Heretofore, dredging of shallow sea with depth of up to 30 meters has been generally practiced by pump suction dredgers or grab bucket ships. However, such suction dredgers or grab buckets are noneffective and not quite safe for dredging of deep sea with depth of more than 60 meters.

The object of the present invention is to provide a deep sea dredger which is capable of dredging the deep sea bottom at high efficiency and with safety.

In the drawings;

FIG. 1 is a schematic side view showing an embodiment of the dredger according to the present invention;

FIG. 2 is a plan view thereof; and

FIG. 3 is a schematic side view of the dredging and suction unit.

Referring to the drawings, the dredger D according to the present invention comprises a floating vessel or barge-like device 1 having a recess la designed to receive a barge 2 therein, a pair of conduit arms 5 each of which is rotatably connected by a pipe joint 4a to the mud inlet port 4 provided on opposite sides of the bow of said vessel 1. A connecting girder 7 is provided between the conduit arms and a dredging and suction unit 11 joined to the girder 7. The conduit arms 5 are suspended from winches 9 by wires. Dredged mud discharger pipes 10 extending from the deck of the vessel 1 are communicated to holds 8 of the barge 2.

wheel 17 for excavating or scooping up mud, silt or the like of the sea bottom.

For dredging the sea bottom by the dredger of the present invention, first the conduit arms 5, which are normally suspended by the winches 9 as shown by dotted chain lines in FIG. 1, are turned about the pipe joints 4a to be lowered into the sea as shown by solid line until the dredging and suction unit 11 is placed on the sea bottom. Then the underwater pump 15 and bucket wheel 17 are operated while pushing the barge 2 in the recess 1a in the dredger D by a push barge or push-boat 3. The bucket wheel 17 is rotated while moving forward as shown in FIG. 3, so that the silt and the like is raked and introduced into the bellmouth l6 and further sucked by the action of the pump 15. Thus the silt is transfered through conduits 18, conduit arms 5, inlets 4 and inside of the vessel 1, and finally discharged into holds 8 of the barge 2 from the discharge pipes 10.

From the foregoing, it will be understood that the dredger according to the present invention has the following advantages:

I. As the dredger is advanced by a push barge, driving means of the vessel 1 is not necessary.

2. As the conduit arms 5 are joined to the dredging and suction until 11 by pipe joints 4a and 6, no bending moment is effected to the arms by rolling of the vessel 1.

3. As the dredging and suction unit 11 is always engaged with the sea bottom during the dredging work, effective dredging may be performed.

4. As silt and the like accumulated on the sea bottom are excavated and stirred by the bucket wheel 17, the silt can be sucked by the pump 15 together with sea water.

What is claimed is:

l. A dredger for use with a push boat comprising a barge, a floating vessel having a recess designed to receive said barge therein and an opening through which silt and the like is discharged out into the barge, conduit arms rotatably supported along opposite sides of the bow of said vessel and communicated into the inside of the vessel, and a dredging and suction unit pivotally joined to the other end of said conduit arms, said dredging and suction unit comprising an underwater pump, a bellmouth connected to said pump, a bucket wheel disposed in front of said bellmouth, guide means comprising skids at the front and rear of said unit mounting said bucket wheel for displacement along the upper surface of said sea bottom with said bucket wheel penetrating the upper layer of said sea bottom to a predetermined depth, and conduits connecting said underwater pump to said conduit arms, whereby dredging of the sea bottom is practiced by pushing said barge and vessel with said push-boat and operating said dredging and suction unit.

2. Apparatus according to claim 1 wherein said floating vessel comprises a barge-like device without motive power for propelling the device, said barge having a recess in its rearward end for receiving the forward end of said push-boat whereby said push-boat is effective to propel both said barge and said floating vessel forwardly to operate said dredging and suction unit.

3. Apparatus according to claim 2 wherein said conduit arms are provided with universal joints to permit rolling of the floating vessel substantially independent of the sliding support of said dredging unit on said bottom. 

1. A dredger for use with a push boat comprising a barge, a floating vessel having a recess designed to receive said barge therein and an opening through which silt and the like is discharged out into the barge, conduit arms rotatably supported along opposite sides of the bow of said vessel and communicated into the inside of the vessel, and a dredging and suction unit pivotally joined to the other end of said conduit arms, said dredging and suction unit comprising an underwater pump, a bellmouth connected to said pump, a bucket wheel disposed in front of said bellmouth, guide means comprising skids at the front and rear of said unit mounting said bucket wheel for displacement along the upper surface of said sea bottom with said bucket wheel penetrating the upper layer of said sea bottom to a predetermined depth, and conduits connecting said underwater pump to said conduit arms, whereby dredging of the sea bottom is practiced by pushing said barge and vessel with said push-boat and operating said dredging and suction unit.
 2. Apparatus according to claim 1 wherein said floating vessel comprises a barge-like device without motive power for propelling the device, said barge having a recess in its rearward end for receiving the forward end of said push-boat whereby said push-boat is effective to propel both said barge and said floating vessel forwardly to operate said dredging and suction unit.
 3. Apparatus according to claim 2 wherein said conduit arms are provided with universal joints to permit rolling of the floating vessel substantially independent of the sliding support of said dredging unit on said bottom. 